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2905fb35 |
1 | package Package::Stash::PP; |
f10f6217 |
2 | use strict; |
3 | use warnings; |
2905fb35 |
4 | # ABSTRACT: pure perl implementation of the Package::Stash API |
f10f6217 |
5 | |
7ef54f40 |
6 | use B; |
f10f6217 |
7 | use Carp qw(confess); |
eb53b1bd |
8 | use Scalar::Util qw(blessed reftype weaken); |
dc378b60 |
9 | use Symbol; |
10 | # before 5.12, assigning to the ISA glob would make it lose its magical ->isa |
11 | # powers |
12 | use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012); |
36cbfbad |
13 | # before 5.10, stashes don't ever seem to drop to a refcount of zero, so |
14 | # weakening them isn't helpful |
15 | use constant BROKEN_WEAK_STASH => ($] < 5.010); |
7ef54f40 |
16 | # before 5.10, the scalar slot was always treated as existing if the |
17 | # glob existed |
18 | use constant BROKEN_SCALAR_INITIALIZATION => ($] < 5.010); |
f4979588 |
19 | |
f4979588 |
20 | =head1 SYNOPSIS |
21 | |
2905fb35 |
22 | use Package::Stash; |
f4979588 |
23 | |
24 | =head1 DESCRIPTION |
25 | |
2905fb35 |
26 | This is a backend for L<Package::Stash> implemented in pure perl, for those without a compiler or who would like to use this inline in scripts. |
f4979588 |
27 | |
28 | =cut |
29 | |
f10f6217 |
30 | sub new { |
31 | my $class = shift; |
e55970bc |
32 | my ($package) = @_; |
774f4f10 |
33 | |
34 | if (!defined($package) || (ref($package) && ref($package) ne 'HASH')) { |
35 | confess "Package::Stash->new must be passed the name of the " |
36 | . "package to access"; |
37 | } |
38 | elsif (ref($package) eq 'HASH') { |
39 | confess "The pure perl implementation of Package::Stash doesn't " |
40 | . "currently support anonymous stashes. You should install " |
41 | . "Package::Stash::XS"; |
42 | } |
12b5662c |
43 | elsif ($package !~ /\A[0-9A-Z_a-z]+(?:::[0-9A-Z_a-z]+)*\z/) { |
ed131e41 |
44 | confess "$package is not a module name"; |
45 | } |
774f4f10 |
46 | |
e55970bc |
47 | return bless { |
eb53b1bd |
48 | 'package' => $package, |
e55970bc |
49 | }, $class; |
f10f6217 |
50 | } |
51 | |
52 | sub name { |
2905fb35 |
53 | confess "Can't call name as a class method" |
54 | unless blessed($_[0]); |
f10f6217 |
55 | return $_[0]->{package}; |
56 | } |
57 | |
58 | sub namespace { |
2905fb35 |
59 | confess "Can't call namespace as a class method" |
60 | unless blessed($_[0]); |
eb53b1bd |
61 | |
36cbfbad |
62 | if (BROKEN_WEAK_STASH) { |
eb53b1bd |
63 | no strict 'refs'; |
36cbfbad |
64 | return \%{$_[0]->name . '::'}; |
eb53b1bd |
65 | } |
36cbfbad |
66 | else { |
67 | return $_[0]->{namespace} if defined $_[0]->{namespace}; |
eb53b1bd |
68 | |
36cbfbad |
69 | { |
70 | no strict 'refs'; |
71 | $_[0]->{namespace} = \%{$_[0]->name . '::'}; |
72 | } |
73 | |
74 | weaken($_[0]->{namespace}); |
eb53b1bd |
75 | |
36cbfbad |
76 | return $_[0]->{namespace}; |
77 | } |
f10f6217 |
78 | } |
79 | |
80 | { |
81 | my %SIGIL_MAP = ( |
82 | '$' => 'SCALAR', |
83 | '@' => 'ARRAY', |
84 | '%' => 'HASH', |
85 | '&' => 'CODE', |
56a29840 |
86 | '' => 'IO', |
f10f6217 |
87 | ); |
88 | |
89 | sub _deconstruct_variable_name { |
90 | my ($self, $variable) = @_; |
91 | |
6a42a16c |
92 | my @ret; |
93 | if (ref($variable) eq 'HASH') { |
94 | @ret = @{$variable}{qw[name sigil type]}; |
95 | } |
96 | else { |
97 | (defined $variable && length $variable) |
98 | || confess "You must pass a variable name"; |
99 | |
100 | my $sigil = substr($variable, 0, 1, ''); |
101 | |
102 | if (exists $SIGIL_MAP{$sigil}) { |
103 | @ret = ($variable, $sigil, $SIGIL_MAP{$sigil}); |
104 | } |
105 | else { |
106 | @ret = ("${sigil}${variable}", '', $SIGIL_MAP{''}); |
107 | } |
108 | } |
f10f6217 |
109 | |
875d2d1d |
110 | # XXX in pure perl, this will access things in inner packages, |
111 | # in xs, this will segfault - probably look more into this at |
112 | # some point |
6a42a16c |
113 | ($ret[0] !~ /::/) |
875d2d1d |
114 | || confess "Variable names may not contain ::"; |
115 | |
6a42a16c |
116 | return @ret; |
f10f6217 |
117 | } |
118 | } |
119 | |
3634ce60 |
120 | sub _valid_for_type { |
121 | my $self = shift; |
122 | my ($value, $type) = @_; |
123 | if ($type eq 'HASH' || $type eq 'ARRAY' |
124 | || $type eq 'IO' || $type eq 'CODE') { |
125 | return reftype($value) eq $type; |
126 | } |
127 | else { |
128 | my $ref = reftype($value); |
d173d3a3 |
129 | return !defined($ref) || $ref eq 'SCALAR' || $ref eq 'REF' || $ref eq 'LVALUE' || $ref eq 'REGEXP' || $ref eq 'VSTRING'; |
3634ce60 |
130 | } |
131 | } |
132 | |
2905fb35 |
133 | sub add_symbol { |
640de369 |
134 | my ($self, $variable, $initial_value, %opts) = @_; |
f10f6217 |
135 | |
6a42a16c |
136 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
137 | |
3634ce60 |
138 | if (@_ > 2) { |
139 | $self->_valid_for_type($initial_value, $type) |
140 | || confess "$initial_value is not of type $type"; |
3634ce60 |
141 | |
4ada57e0 |
142 | # cheap fail-fast check for PERLDBf_SUBLINE and '&' |
143 | if ($^P and $^P & 0x10 && $sigil eq '&') { |
640de369 |
144 | my $filename = $opts{filename}; |
145 | my $first_line_num = $opts{first_line_num}; |
4ada57e0 |
146 | |
640de369 |
147 | (undef, $filename, $first_line_num) = caller |
4ada57e0 |
148 | if not defined $filename; |
640de369 |
149 | |
150 | my $last_line_num = $opts{last_line_num} || ($first_line_num ||= 0); |
4ada57e0 |
151 | |
152 | # http://perldoc.perl.org/perldebguts.html#Debugger-Internals |
50419d91 |
153 | $DB::sub{$self->name . '::' . $name} = "$filename:$first_line_num-$last_line_num"; |
4ada57e0 |
154 | } |
155 | } |
f10f6217 |
156 | |
50419d91 |
157 | my $namespace = $self->namespace; |
158 | my $gv = $namespace->{$name} || Symbol::gensym; |
159 | *$gv = ref $initial_value ? $initial_value : \$initial_value; |
160 | $namespace->{$name} = *$gv; |
f10f6217 |
161 | } |
162 | |
2905fb35 |
163 | sub remove_glob { |
f10f6217 |
164 | my ($self, $name) = @_; |
65b8253b |
165 | delete $self->namespace->{$name}; |
f10f6217 |
166 | } |
167 | |
2905fb35 |
168 | sub has_symbol { |
f10f6217 |
169 | my ($self, $variable) = @_; |
170 | |
6a42a16c |
171 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
172 | |
173 | my $namespace = $self->namespace; |
174 | |
175 | return unless exists $namespace->{$name}; |
176 | |
177 | my $entry_ref = \$namespace->{$name}; |
178 | if (reftype($entry_ref) eq 'GLOB') { |
f7543739 |
179 | if ($type eq 'SCALAR') { |
7ef54f40 |
180 | if (BROKEN_SCALAR_INITIALIZATION) { |
181 | return defined ${ *{$entry_ref}{$type} }; |
182 | } |
183 | else { |
184 | return B::svref_2object($entry_ref)->SV->isa('B::SV'); |
185 | } |
f7543739 |
186 | } |
187 | else { |
188 | return defined *{$entry_ref}{$type}; |
189 | } |
f10f6217 |
190 | } |
191 | else { |
192 | # a symbol table entry can be -1 (stub), string (stub with prototype), |
193 | # or reference (constant) |
194 | return $type eq 'CODE'; |
195 | } |
196 | } |
197 | |
2905fb35 |
198 | sub get_symbol { |
e55803fc |
199 | my ($self, $variable, %opts) = @_; |
f10f6217 |
200 | |
6a42a16c |
201 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
202 | |
203 | my $namespace = $self->namespace; |
204 | |
7486ccf3 |
205 | if (!exists $namespace->{$name}) { |
dc378b60 |
206 | if ($opts{vivify}) { |
207 | if ($type eq 'ARRAY') { |
208 | if (BROKEN_ISA_ASSIGNMENT) { |
2905fb35 |
209 | $self->add_symbol( |
dc378b60 |
210 | $variable, |
211 | $name eq 'ISA' ? () : ([]) |
212 | ); |
213 | } |
214 | else { |
2905fb35 |
215 | $self->add_symbol($variable, []); |
dc378b60 |
216 | } |
217 | } |
218 | elsif ($type eq 'HASH') { |
2905fb35 |
219 | $self->add_symbol($variable, {}); |
dc378b60 |
220 | } |
221 | elsif ($type eq 'SCALAR') { |
2905fb35 |
222 | $self->add_symbol($variable); |
dc378b60 |
223 | } |
224 | elsif ($type eq 'IO') { |
2905fb35 |
225 | $self->add_symbol($variable, Symbol::geniosym); |
dc378b60 |
226 | } |
227 | elsif ($type eq 'CODE') { |
228 | confess "Don't know how to vivify CODE variables"; |
229 | } |
230 | else { |
231 | confess "Unknown type $type in vivication"; |
232 | } |
5d3589c8 |
233 | } |
e55803fc |
234 | else { |
4723417a |
235 | return undef; |
e55803fc |
236 | } |
30d1a098 |
237 | } |
f10f6217 |
238 | |
239 | my $entry_ref = \$namespace->{$name}; |
240 | |
241 | if (ref($entry_ref) eq 'GLOB') { |
242 | return *{$entry_ref}{$type}; |
243 | } |
244 | else { |
245 | if ($type eq 'CODE') { |
d6213159 |
246 | # XXX we should really be able to support arbitrary anonymous |
247 | # stashes here... (not just via Package::Anon) |
248 | if (blessed($namespace) && $namespace->isa('Package::Anon')) { |
249 | # ->can will call gv_init for us |
250 | $namespace->bless(\(my $foo))->can($name); |
251 | return *{ $namespace->{$name} }{CODE}; |
252 | } |
253 | else { |
254 | no strict 'refs'; |
255 | return \&{ $self->name . '::' . $name }; |
256 | } |
f10f6217 |
257 | } |
258 | else { |
259 | return undef; |
260 | } |
261 | } |
262 | } |
263 | |
2905fb35 |
264 | sub get_or_add_symbol { |
e55803fc |
265 | my $self = shift; |
2905fb35 |
266 | $self->get_symbol(@_, vivify => 1); |
e55803fc |
267 | } |
268 | |
2905fb35 |
269 | sub remove_symbol { |
f10f6217 |
270 | my ($self, $variable) = @_; |
271 | |
6a42a16c |
272 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
273 | |
274 | # FIXME: |
9a3d1390 |
275 | # no doubt this is grossly inefficient and |
f10f6217 |
276 | # could be done much easier and faster in XS |
277 | |
b1a00d0e |
278 | my ($scalar_desc, $array_desc, $hash_desc, $code_desc, $io_desc) = ( |
f10f6217 |
279 | { sigil => '$', type => 'SCALAR', name => $name }, |
280 | { sigil => '@', type => 'ARRAY', name => $name }, |
281 | { sigil => '%', type => 'HASH', name => $name }, |
282 | { sigil => '&', type => 'CODE', name => $name }, |
b1a00d0e |
283 | { sigil => '', type => 'IO', name => $name }, |
f10f6217 |
284 | ); |
285 | |
b1a00d0e |
286 | my ($scalar, $array, $hash, $code, $io); |
f10f6217 |
287 | if ($type eq 'SCALAR') { |
2905fb35 |
288 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
289 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
290 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
291 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
292 | } |
293 | elsif ($type eq 'ARRAY') { |
7ef54f40 |
294 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
295 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
296 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
297 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
298 | } |
299 | elsif ($type eq 'HASH') { |
7ef54f40 |
300 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
301 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
302 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
303 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
304 | } |
305 | elsif ($type eq 'CODE') { |
7ef54f40 |
306 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
307 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
308 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
309 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
b1a00d0e |
310 | } |
311 | elsif ($type eq 'IO') { |
7ef54f40 |
312 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
313 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
314 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
315 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
f10f6217 |
316 | } |
317 | else { |
318 | confess "This should never ever ever happen"; |
319 | } |
320 | |
2905fb35 |
321 | $self->remove_glob($name); |
f10f6217 |
322 | |
7ef54f40 |
323 | $self->add_symbol($scalar_desc => $scalar) if defined $scalar; |
2905fb35 |
324 | $self->add_symbol($array_desc => $array) if defined $array; |
325 | $self->add_symbol($hash_desc => $hash) if defined $hash; |
326 | $self->add_symbol($code_desc => $code) if defined $code; |
327 | $self->add_symbol($io_desc => $io) if defined $io; |
f10f6217 |
328 | } |
329 | |
2905fb35 |
330 | sub list_all_symbols { |
f10f6217 |
331 | my ($self, $type_filter) = @_; |
332 | |
333 | my $namespace = $self->namespace; |
334 | return keys %{$namespace} unless defined $type_filter; |
335 | |
336 | # NOTE: |
9a3d1390 |
337 | # or we can filter based on |
f10f6217 |
338 | # type (SCALAR|ARRAY|HASH|CODE) |
339 | if ($type_filter eq 'CODE') { |
340 | return grep { |
25c87f5c |
341 | # any non-typeglob in the symbol table is a constant or stub |
342 | ref(\$namespace->{$_}) ne 'GLOB' |
343 | # regular subs are stored in the CODE slot of the typeglob |
d1f721b3 |
344 | || defined(*{$namespace->{$_}}{CODE}) |
345 | } keys %{$namespace}; |
346 | } |
347 | elsif ($type_filter eq 'SCALAR') { |
348 | return grep { |
7ef54f40 |
349 | BROKEN_SCALAR_INITIALIZATION |
350 | ? (ref(\$namespace->{$_}) eq 'GLOB' |
351 | && defined(${*{$namespace->{$_}}{'SCALAR'}})) |
352 | : (do { |
353 | my $entry = \$namespace->{$_}; |
354 | ref($entry) eq 'GLOB' |
355 | && B::svref_2object($entry)->SV->isa('B::SV') |
356 | }) |
d1f721b3 |
357 | } keys %{$namespace}; |
358 | } |
359 | else { |
360 | return grep { |
361 | ref(\$namespace->{$_}) eq 'GLOB' |
362 | && defined(*{$namespace->{$_}}{$type_filter}) |
f10f6217 |
363 | } keys %{$namespace}; |
f10f6217 |
364 | } |
365 | } |
f4979588 |
366 | |
2905fb35 |
367 | sub get_all_symbols { |
368 | my ($self, $type_filter) = @_; |
369 | |
370 | my $namespace = $self->namespace; |
371 | return { %{$namespace} } unless defined $type_filter; |
372 | |
373 | return { |
374 | map { $_ => $self->get_symbol({name => $_, type => $type_filter}) } |
375 | $self->list_all_symbols($type_filter) |
376 | } |
377 | } |
378 | |
0992f4ec |
379 | =head1 BUGS |
380 | |
2905fb35 |
381 | =over 4 |
382 | |
2905fb35 |
383 | =item * remove_symbol also replaces the associated typeglob |
384 | |
385 | This can cause unexpected behavior when doing manipulation at compile time - |
386 | removing subroutines will still allow them to be called from within the package |
387 | as subroutines (although they will not be available as methods). This can be |
388 | considered a feature in some cases (this is how L<namespace::clean> works, for |
389 | instance), but should not be relied upon - use C<remove_glob> directly if you |
390 | want this behavior. |
391 | |
cdb543b5 |
392 | =item * Some minor memory leaks |
393 | |
394 | The pure perl implementation has a couple minor memory leaks (see the TODO |
395 | tests in t/20-leaks.t) that I'm having a hard time tracking down - these may be |
396 | core perl bugs, it's hard to tell. |
397 | |
2905fb35 |
398 | =back |
0992f4ec |
399 | |
400 | Please report any bugs through RT: email |
401 | C<bug-package-stash at rt.cpan.org>, or browse to |
402 | L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Package-Stash>. |
403 | |
f4979588 |
404 | =head1 SEE ALSO |
405 | |
f4979588 |
406 | =over 4 |
407 | |
988beb41 |
408 | =item * L<Class::MOP::Package> |
f4979588 |
409 | |
988beb41 |
410 | This module is a factoring out of code that used to live here |
f4979588 |
411 | |
412 | =back |
413 | |
0992f4ec |
414 | =head1 SUPPORT |
415 | |
416 | You can find this documentation for this module with the perldoc command. |
417 | |
418 | perldoc Package::Stash |
419 | |
420 | You can also look for information at: |
421 | |
422 | =over 4 |
423 | |
424 | =item * AnnoCPAN: Annotated CPAN documentation |
425 | |
426 | L<http://annocpan.org/dist/Package-Stash> |
427 | |
428 | =item * CPAN Ratings |
429 | |
430 | L<http://cpanratings.perl.org/d/Package-Stash> |
431 | |
432 | =item * RT: CPAN's request tracker |
433 | |
434 | L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Package-Stash> |
435 | |
436 | =item * Search CPAN |
437 | |
438 | L<http://search.cpan.org/dist/Package-Stash> |
439 | |
440 | =back |
441 | |
442 | =head1 AUTHOR |
443 | |
444 | Jesse Luehrs <doy at tozt dot net> |
445 | |
446 | Mostly copied from code from L<Class::MOP::Package>, by Stevan Little and the |
447 | Moose Cabal. |
448 | |
a912fc4b |
449 | =begin Pod::Coverage |
450 | |
451 | BROKEN_ISA_ASSIGNMENT |
452 | add_symbol |
453 | get_all_symbols |
454 | get_or_add_symbol |
455 | get_symbol |
456 | has_symbol |
457 | list_all_symbols |
458 | name |
459 | namespace |
460 | new |
461 | remove_glob |
462 | |
463 | =end Pod::Coverage |
464 | |
f4979588 |
465 | =cut |
466 | |
467 | 1; |